ftrace: Make CALLER_ADDRx macros more generic

Most archs with HAVE_ARCH_CALLER_ADDR have pretty much the same
definitions of CALLER_ADDRx(n). Instead of duplicating the code for all
the archs, define a ftrace_return_address0() and
ftrace_return_address(n) that can be overwritten by the archs if they
need to do something different. Instead of 7 macros in every arch, we
now only have at most 2 (and actually only 1 as
ftrace_return_address0() should be the same for all archs).

The CALLER_ADDRx(n) will now be defined in linux/ftrace.h and use the
ftrace_return_address*(n?) macros. This removes a lot of the duplicate
code.

Link: http://lkml.kernel.org/p/1400585464-30333-1-git-send-email-takahiro.akashi@linaro.org

Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
index ae9504b..2018751 100644
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h
@@ -616,25 +616,27 @@
 #endif
 }
 
-#ifndef HAVE_ARCH_CALLER_ADDR
+/* All archs should have this, but we define it for consistency */
+#ifndef ftrace_return_address0
+# define ftrace_return_address0 __builtin_return_address(0)
+#endif
+
+/* Archs may use other ways for ADDR1 and beyond */
+#ifndef ftrace_return_address
 # ifdef CONFIG_FRAME_POINTER
-#  define CALLER_ADDR0 ((unsigned long)__builtin_return_address(0))
-#  define CALLER_ADDR1 ((unsigned long)__builtin_return_address(1))
-#  define CALLER_ADDR2 ((unsigned long)__builtin_return_address(2))
-#  define CALLER_ADDR3 ((unsigned long)__builtin_return_address(3))
-#  define CALLER_ADDR4 ((unsigned long)__builtin_return_address(4))
-#  define CALLER_ADDR5 ((unsigned long)__builtin_return_address(5))
-#  define CALLER_ADDR6 ((unsigned long)__builtin_return_address(6))
+#  define ftrace_return_address(n) __builtin_return_address(n)
 # else
-#  define CALLER_ADDR0 ((unsigned long)__builtin_return_address(0))
-#  define CALLER_ADDR1 0UL
-#  define CALLER_ADDR2 0UL
-#  define CALLER_ADDR3 0UL
-#  define CALLER_ADDR4 0UL
-#  define CALLER_ADDR5 0UL
-#  define CALLER_ADDR6 0UL
+#  define ftrace_return_address(n) 0UL
 # endif
-#endif /* ifndef HAVE_ARCH_CALLER_ADDR */
+#endif
+
+#define CALLER_ADDR0 ((unsigned long)ftrace_return_address0)
+#define CALLER_ADDR1 ((unsigned long)ftrace_return_address(1))
+#define CALLER_ADDR2 ((unsigned long)ftrace_return_address(2))
+#define CALLER_ADDR3 ((unsigned long)ftrace_return_address(3))
+#define CALLER_ADDR4 ((unsigned long)ftrace_return_address(4))
+#define CALLER_ADDR5 ((unsigned long)ftrace_return_address(5))
+#define CALLER_ADDR6 ((unsigned long)ftrace_return_address(6))
 
 #ifdef CONFIG_IRQSOFF_TRACER
   extern void time_hardirqs_on(unsigned long a0, unsigned long a1);